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1993 Acura Legend Cooling Fan Control

I noticed one day that my car was overheating so I checked the cooling fans and they were not on. I turned the AC on and as I figured they worked. I checked all the fuses and relays and they all work so I tracked the problem to the cooling fan control that is located on the bottom right of the radiator. I pulled the plastic off the bottom of the car and tried to take it off and nothing happened. It is spinning and won’t come out. I can feel a bit of a click as I turn it but it won’t come out. I have looked for a crack in the tank around it that wouldn’t let the threads catch but haven’t found anything. I have tried to pull as I turn it and nothing works. The part was only $20 or so and a new radiator with coolant and ATF will be around $200 and I can’t spend that money right now and I am freaking out. Thank you for the time.

People who own cars shouldn’t freak out over $200. Cars are expensive to own and operate. It’s just a fact of life.

What is the main question here? How do you know you need a new radiator?

Did you replace the radiator fan relay or radiator fan switch? Does it still overheat?

If you want to minimize costs, learn to fix the car yourself, get a good Acura repair manual. Find replacement parts at U-Pull-It salvage yards, on Ebay, or aftermarket parts on the internet.

You won’t lose much ATF even if you have to remove the radiator. Coolant is cheap.

Yes I understand cars are expensive and I normally wouldn’t worry about it but I am moving and trying to spend the least amount of money I can to be safe. I do work on my car myself and I might end up going to a salvage yard and getting one for cheaper but I am trying to avoid having to replace the radiator in general. I am asking the question to see if anyone else has run into a problem like this and what they did. I don’t see any reason it wouldn’t just screw out but it is just spinning and it seems to feel like it is clicking as I turn. It doesn’t make any noises but you can feel it click as you turn it. It turns both ways without any resistance change. Once again thank you for your time.

Is this the part you’re trying to remove?

http://www.rockauto.com/catalog/x,carcode,1000753,parttype,4312

Yes.

Can you shoot a fairly good picture of it on your car & post? Try to indicate what you’re doing with it in terms of removal. Are you using a socket? Is the socket the right size? Is the socket actually getting firmly onto the hex part of it? If all of that was yes AND maybe the threads were stripped then it would be leaking coolant. Is it?

I can post a picture in a few hours but for now it is connected to the bottom plastic tank of the radiator. I initially used a wrench and switched to a pair of vice grips to try and pull and turn. It has not been leaking that’s why I am so confused. I will post a few pictures soon. Thank you both for your time.

If you just need to keep it from overheating while you move, you should be able to jumper the plug from that heat sensor to turn the fan on low speed and let it run all the while your car is running. If the fan is always hot, you will have to either run wires to the passenger compartment or pop the hood and turn it off every time you turn off the car. Not ideal, but not overheating.

I took a few pictures so everyone can get a better idea of what I am talking about. Any thoughts?

If you’re turning on that brass portion and it is just spinning and that’s it, and spinning in either direction with about the same resistance, then the threads are stripped presumably on the radiator.

If you wedge something in there to pry outward while you spin it out you might get it going out. Then you might be able to repair the threads well enough to make a new one work. Actually a bunch of teflon tape on the thread of a new one might even work well enough. You’re only looking at about 16lb of pressure. It might be easier to remove the radiator to deal with it.

Before you started all of this did you happen to check the sensor? It will have a set of ohm specs & you just measure resistance at the two pins. Then you hopefully checked the wiring to the sensor?

The problem might be that the sensor threads into a brass nut-sert on the plastic tank. On some plastic radiator tanks they’ll mold a hex recess into the tank. Then they’ll take a hex nut-sert, set it in the hex recess on the tank and then take a mandrel and thread into the nut-sert and expand the nut-sert inside the the tank to lock it down. This prevents the nut-sert from spinning when removing the sensor. It could be that the nut-sert is spinning with the sensor when trying to remove it. And the clicking sound is the nut-sert hex striping past the hex molded into the tank.

Tester

I measured the resistance on the switch and came back with 15.88 kohms and it dropped by 0.1 ohm every second I was connected. I measured the resistance on the wires by plugging into the terminals where the switch plugs in and got 1.999 kohms. What does this mean? Thank you.

I just measured the resistance in the new switch and then the old switch and the old one is about 12khoms and the new one is about 11kohms. Is that close enough? The wire still measures the same.

The sensor itself is probably fine, but what you need to know is how the resistance changes as its temp changes. The heating/cooling changes the resistance. That’s what gives the temp signal. Somewhere in the world (e.g. in a repair manual) there will be a set of specs that will tell you what ohms should be given specific temps.

The wire resistance you need to measure on each wire - as in from one end to the other. It should be really low - like hopefully near zero. You’ll probably need a wiring diagram to help you follow the wires. I’d have to guess that the temp signal goes to the ECU which then controls the fan. But I don’t know this car, so that is just a guess. A wiring diagram would tell you where those wires end up.

You might try Autozone’s free online repair info. Or a basic Haynes manual ($20 at any auto parts store) might have it.

Hello again everyone. I have narrowed my problem down to the sensor and I can not get the sensor off. I have looked at the other bolts and such on the lower radiator tank and have realized it is the metal thread insert that is spinning and the tank is just not grabbing it so I can not get the sensor out. I have tried a wrench and a small crowbar to pry it up and I have tried vice grips spinning and pulling and nothing works. Does anyone have any ideas? I don’t want to have to spend $200+ for a $20 fix. Thank you for any input. Philip.